feat(pricing): remove DeepL from all user-facing surfaces

Pricing: 'deepl' removed from plan provider lists and the comparison
table row. Landing and pricing copy (13 locales) no longer mention
DeepL (65 values cleaned, 39 dead keys deleted: pricing.comparison.deepl,
providerTheme.classic.deepl.*).

Providers: available-provider responses are filtered so a DeepL entry
from the backend can never surface in the engine picker or the services
page; DeepL theme entry and static lib/api.ts list entry removed.

Admin: DeepL config card, type fields, defaults and fallback-chain
mentions removed; stats/chart/status maps and mock data cleaned.

Backend adapter untouched — DeepL is invisible app-wide via the UI
filter; removing the Python adapter itself is a separate step if wanted.

Verified: build exit 0, vitest 9/9, eslint clean on touched files,
zero 'deepl' occurrences outside the two intentional UI filters.

frontend/src/lib/i18n/messages/fr/landing.json

@@ -52,7 +52,7 @@
   "landing.layout.p5.title": "En-têtes et pieds de page",
   "landing.layout.p5.desc": "En-têtes, pieds de page et notes ne sont jamais oubliés.",
   "landing.layout.p6.title": "130+ langues",
-  "landing.layout.p6.desc": "Google Traduction, DeepL et moteurs IA haute performance.",
+  "landing.layout.p6.desc": "Google Traduction et moteurs IA haute performance.",
   "landing.formats.title": "Chaque format,",
   "landing.formats.title2": "chaque élément",
   "landing.formats.subtitle": "Nous traduisons ce que les autres oublient. Votre entreprise mérite une documentation irréprochable.",
@@ -93,7 +93,7 @@
   "landing.pricing.starter.desc": "Pour les particuliers et petits projets",
   "landing.pricing.starter.f1": "50 documents / mois",
   "landing.pricing.starter.f2": "Jusqu'à 50 pages par doc",
-  "landing.pricing.starter.f3": "Google Traduction + DeepL",
+  "landing.pricing.starter.f3": "Google Traduction",
   "landing.pricing.starter.f4": "Fichiers jusqu'à 10 Mo",
   "landing.pricing.starter.cta": "Commencer",
   "landing.pricing.pro.name": "Pro",
@@ -101,7 +101,7 @@
   "landing.pricing.pro.f1": "200 documents / mois",
   "landing.pricing.pro.f2": "Jusqu'à 200 pages par doc",
   "landing.pricing.pro.f3": "Traduction par IA",
-  "landing.pricing.pro.f4": "Google + DeepL inclus",
+  "landing.pricing.pro.f4": "Google inclus",
   "landing.pricing.pro.f5": "Glossaires et prompts",
   "landing.pricing.pro.f6": "Support prioritaire",
   "landing.pricing.pro.cta": "Essayer Pro",

frontend/src/lib/i18n/messages/fr/pricing.json

@@ -27,14 +27,14 @@
   "pricing.plans.free.feat5": "Support communautaire",
   "pricing.plans.starter.feat1": "50 documents / mois",
   "pricing.plans.starter.feat2": "Jusqu'à 50 pages par document",
-  "pricing.plans.starter.feat3": "Google Traduction + DeepL",
+  "pricing.plans.starter.feat3": "Google Traduction",
   "pricing.plans.starter.feat4": "Fichiers jusqu'à 10 Mo",
   "pricing.plans.starter.feat5": "Support par e-mail",
   "pricing.plans.starter.feat6": "Historique 30 jours",
   "pricing.plans.pro.feat1": "200 documents / mois",
   "pricing.plans.pro.feat2": "Jusqu'à 200 pages par document",
   "pricing.plans.pro.feat3": "Traduction IA Essentielle",
-  "pricing.plans.pro.feat4": "Google Traduction + DeepL",
+  "pricing.plans.pro.feat4": "Google Traduction",
   "pricing.plans.pro.feat5": "Fichiers jusqu'à 25 Mo",
   "pricing.plans.pro.feat6": "Glossaires personnalisés",
   "pricing.plans.pro.feat7": "Support prioritaire",
@@ -83,7 +83,6 @@
   "pricing.comparison.pagesMaxPerDoc": "Pages max / document",
   "pricing.comparison.maxFileSize": "Taille max fichier",
   "pricing.comparison.googleTranslation": "Google Traduction",
-  "pricing.comparison.deepl": "DeepL",
   "pricing.comparison.aiEssential": "Traduction IA Essentielle",
   "pricing.comparison.aiPremium": "Traduction IA Premium",
   "pricing.comparison.apiAccess": "Accès API",

frontend/src/lib/i18n/messages/fr/providerTheme.json

@@ -22,8 +22,6 @@
   "providerTheme.default.desc": "Traduction par grand modèle linguistique (LLM) avec analyse sémantique avancée.",
   "providerTheme.classic.google.label": "Google Traduction",
   "providerTheme.classic.google.desc": "Traduction ultra-rapide couvrant plus de 130 langues. Recommandé pour les flux généraux.",
-  "providerTheme.classic.deepl.label": "DeepL Pro",
-  "providerTheme.classic.deepl.desc": "Traduction haute précision réputée pour sa fluidité et ses formulations naturelles.",
   "providerTheme.classic.google_cloud.label": "Google Cloud API",
   "providerTheme.classic.google_cloud.desc": "Moteur cloud professionnel optimisé pour le traitement de gros volumes de documents."
 }